In this article, I discuss some of the questions that arise for environmental historians from recent historical and theoretical studies of waste. This article is not an attempt to methodically review the entire corpus of work on waste within the social sciences and humanities. Rather I seek to draw attention to the ways in which waste constitutes an important problem for environmental history in particular. The article is in four sections. The first two deal with conceptual approaches to waste that are presently popular and draws an analytical distinction between waste and dirt, terms that are often collapsed into one another but which, when kept distinct, can do more useful work. The third and fourth sections discuss present historical treatments of waste, their capacities and limitations, before I mark out possible ways in which historians can take seriously the analytical distinctiveness of ‘waste’.